Electronic system having electronic apparatus with built-in heat generating component and cooling apparatus to cool the electronic apparatus

ABSTRACT

A cooling apparatus includes a cooling module having an electrically-driven cooling device. The cooling module is adapted to couple with a portable electronic apparatus having a heat generating component and a first connector to supply power. A second connector is provided to be electrically connected to the cooling device. The second connector is connected to the first connector when it is coupled with the portable electronic apparatus to supply the cooling device with the power received from the first connector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority fromJapanese Patent Application No. 2001-029902, filed Feb. 6, 2001.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an electronic system having anelectronic apparatus such as portable computer, and a cooling apparatusto be used by coupling with the electronic apparatus.

2. Discussion of the Related Art

The power consumption of a portable electronic apparatus, such as anotebook computer, has been increasing due to higher processing speedsand multi-functionality of the microprocessor, and the microprocessorheat value tends to increase rapidly in proportion. Therefore, it isnecessary to improve the heat radiation from the microprocessor in orderto secure stable operation of portable computers.

As a countermeasure thereof, a conventional portable computer contains aheat sink thermally connected to the microprocessor, and there is anelectric fan to provide cooling air to the heat sink, which cools down ahot microprocessor.

According to this conventional cooling method, as the cooling airsupplied from the electric fan becomes a cooling medium for absorbingthe heat from the microprocessor, the microprocessor cooling capacitydepends largely on the blowing capacity of the electric fan. As aresult, if the flow of cooling air is increased to enhance themicroprocessor cooling capacity, the electric fan typically increases insize. Consequently, a large space would be required inside the housingof a portable computer for installing a bulky electric fan.

In general, for a portable computer, the housing is designed to be thinand compact because portability is a critical element for enhancing itsproduct value. Therefore, a space for containing a large electric fan ofa large blowing capacity or a draft air path for cooling air is toolarge be secured in the housing. As a result, there may be a concernthat in the conventional cooling method, the microprocessor coolingcapacity may be insufficient or may reach the thermal limit.

On the other hand, it is difficult to secure an installation section ofconnectors for connecting, for example, input/output devices and a spacefor containing a CD-ROM drive unit, due to the thinning of the housing,for portable computers. Therefore, recent portable computers areprovided with an expansion connector and can obtain an expansion abilitycomparable to that of desktop computers, by connecting this expansionconnector to an expansion apparatus called a docking station.

The conventional expansion apparatus typically includes a box-shapeapparatus main body with built-in apparatuses for function expansion,such as a CD-ROM drive unit, a DVD drive unit, or the like. Theapparatus main body has a top face on which the housing of the portablecomputer is placed, and a relay connector is arranged on this top face.The relay connector fits into the aforementioned expansion connectorwhen the housing is put on the top face. A mutual fitting of theseconnectors allows an electric conduction of signal path for variouscontrol signals, such as mutual logical address, or a data path of theportable computer and the expansion apparatuses.

Among such kinds of expansion apparatuses, one for installing a heatsink in the apparatus main body and for cooling a heat sink with airblown by an electric fan is known. According to this expansionapparatus, when the housing of the portable computer is placed on theapparatus main body, this housing comes into contact with the heat sink.Consequently, heat conducted from the microprocessor to the housing isdissipated by heat conduction to the heat sink and borne by the flow ofcooling air radiated outside the housing. Therefore, the portablecomputer may be cooled by using the expansion apparatus, therebyenhancing the cooling function of the portable computer.

However, an extremely thin and light notebook-type portable computer isdesigned to be mobile, and adapted to receive/transmit data from/to aclient, or for use in a presentation at the premises of a client.Therefore, in the conventional configuration for supporting themicroprocessor cooling by means of an expansion apparatus, it isnecessary to carry all of the times a heavy and bulky expansionapparatus together with the portable computer. Consequently, it becomesimpossible to put the portable computer in a bag, or the like, and carryabout it easily, thus sacrificing its inherent portability.

In the case of just carrying solely the portable computer, themicroprocessor cooling capacity may be insufficient. Therefore,especially when the microprocessor is tasked to execute complicatedcalculations and processing, there is a fear that the temperature of themicroprocessor may exceed the operational limits. If the temperature ofthe microprocessor becomes too high, the processing speed may becomeslower, or the operation may become impossible due to thermal overload.Consequently, it becomes impossible to completely utilize all of theperformance features of the microprocessor.

BRIEF SUMMARY OF THE INVENTION

The present invention has been devised based on such a situation andprovides an electronic system capable of obtaining a desired coolingperformance without sacrificing the portability, and a cooling apparatusused for a portable electronic system, such as a notebook computer.

Additional objects and advantages of the invention will be set forth inthe description which follows, and in part will be obvious from thedescription, or may be learned by practice of the invention. The objectsand advantages of the invention may be realized and obtained by means ofthe instrumentalities and combinations particularly pointed outhereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a perspective view of an electronic system having a portablecomputer, a cooling apparatus, and an expansion apparatus according toan embodiment of the present invention;

FIG. 2 is a perspective view of the electronic system showing a statewhere the portable computer and the cooling apparatus are separated;

FIG. 3 is a cross-sectional view of the electronic system showing astate where the portable computer and the cooling apparatus areseparated;

FIG. 4 is a perspective view of the portable computer showing a statewhere a cover is attached to a bottom wall of a housing;

FIG. 5 is a perspective view of the portable computer showing apositional relation between a heat conductive sheet and a heatconnection surface of a first heat sink in a state where the cover isdetached from the bottom wall of the housing;

FIG. 6 is a perspective view of a cooling apparatus;

FIG. 7 is a cross-sectional view of the electronic system showing astate where the portable computer and the cooling apparatus are linked;

FIG. 8 is a cross-sectional view of the electronic apparatus systemshowing a positional relation between a first cooling module in thecooling apparatus and a cooling unit in the housing, in a state wherethe portable computer and the cooling apparatus are linked;

FIG. 9 is a perspective view of the cooling apparatus showing apositional relation between a second heat sink and an operationmechanism;

FIG. 10 is a plan view of the cooling apparatus showing a positionalrelation between a slider slid to a second position, a first coolingmodule, and a switch operation lever;

FIG. 11 is a plan view of the cooling apparatus showing a positionalrelation between a slider slid to a first position, the first coolingmodule, and the switch operation lever;

FIG. 12 is a side view of the electronic system schematically showingthe state where the portable computer and the cooling apparatus arelinked;

FIG. 13 is a perspective view of the electronic system showing a statewhere the portable computer and an expansion apparatus are linked;

FIG. 14 is a perspective view of the electronic system showing a statewhere the portable computer and the expansion apparatus are separated;

FIG. 15 is a cross-sectional view of the electronic system showing astate where the portable computer and the expansion apparatus areseparated;

FIG. 16 is a cross-sectional view of the electronic system showing apositional relation between the cooling unit of the portable computerand the second cooling module of the expansion apparatus;

FIG. 17 is a cross-sectional view of the electronic system showing astate where the portable computer and the expansion apparatus arelinked;

FIG. 18 a plan view of the second cooling module housed inside a base;and

FIG. 19 is a side view of the electronic system schematically showing astate where the portable computer and the expansion apparatus arelinked.

DETAILED DESCRIPTION

Now, an embodiment of the present invention will be described based onthe drawings applied to a portable computer.

As shown in FIG. 1, an electronic system includes a portable computer 1as an electronic apparatus, a cooling apparatus 2 for cooling of theportable computer 1, and an expansion apparatus 3 to be used forexpanding the functionality of the portable computer 1.

As shown in FIG. 2, the portable computer 1 is constituted by a computermain body 5 and a display unit 6 supported by the computer main body 5.The computer main body 5 includes a housing 7. The housing 7 (shown inFIG. 1) is a flat box-shape having a bottom wall 7 a, a top wall 7 b, afront wall 7 c, right and left side walls 7 d, and a back wall 7 e.

The top wall 7 b of the housing 7 has a palm rest 8 and a keyboardattachment section 9. The palm rest 8 extends in the width direction ofthe housing 7 in a forward half section of the housing 7. The keyboardattachment section 9 is positioned behind the palm rest 8 and a keyboard11 is installed on the keyboard attachment section 9.

The display unit 6 includes a display housing 12 and a liquid crystalpanel 13 housed in the display housing 12. The liquid crystal panel 13is exposed outward through an opening 14 at the front face of thedisplay housing 12. The display housing 12 is linked with a rear endsection of the housing 7 through a hinge device (not shown). Therefore,the display unit 6 can rotate from a closed position where it is pusheddown so as to cover the palm rest 8 and the keyboard 11 from the top, toan open position where it is erected so as to expose the keyboard 11 andthe liquid crystal panel 13.

As shown in FIG. 3, the housing 7 contains a circuit board 16. Thecircuit board 16 has a lower surface facing to the bottom wall 7 a, anda first expansion connector 17 is mounted on the rear end section of thelower surface of the circuit board 16. The first expansion connector 17is opposed to a connector connection port 18 (shown in FIG. 4) openingon the bottom wall 7 a. The connector connection port 18 is covered witha shutter 19 that can open and close.

As shown in FIG. 4, a power supply connector 21 is arranged at the rightend section of the back wall 7 e of the housing 7. The power supplyconnector 21 is for connecting a power supply cord (not shown). Thepower supply connector 21 is mounted on the circuit board 16, and iselectrically connected to a power supply circuit on the circuit board16.

A battery pack 22 serving as a power supply during carriage of theportable computer is supported detachably on the middle section of theback wall 7 e of the housing 7. The battery pack 22 is electricallyconnected to the power supply circuit on the circuit board 16.

A semiconductor package 23 as a heat generating component is mounted onthe lower face of the circuit board 16. The semiconductor package 23 mayhave a microprocessor at the center of the portable computer 1, and mayhave an IC chip 24 generating heat during the operation. When processingmultimedia information such as character, sound, and images at highspeeds, the IC chip 24 generates a large amount of heat. Therefore, thesemiconductor package 23 requires cooling in order to maintain a safeoperational temperature.

As shown in FIG. 3 and FIG. 8, the housing 7 has a built-in cooling unit25 for cooling down the semiconductor package 23. The cooling unit 25includes a first heat sink 26 and an electric fan 27. The first heatsink 26 is constituted by a metal material excellent in heatconductivity, such as aluminum alloy, for example. The first heat sink26 includes a flat plate shape having a heat receiving portion 28 and aheat exchanging portion 29. The first heat sink 26 is arranged along thebottom wall 7 a of the housing 7 and a plurality of points thereof arefixed to the bottom wall 7 a and the circuit board 16 through screws 30.

The heat receiving portion 28 is opposed to the semiconductor package23. The heat receiving portion 28 is thermally connected to the IC chip24 of the semiconductor package 23 through a heat dissipation plate 31and grease 32. The heat receiving portion 28 has a flat heat connectionsurface 34 at the side opposed to the semiconductor package 23. The heatconnection surface 34 is adjacent to the bottom wall 7 a of the housing7, and is covered with a soft heat conductive sheet 35 as a heatconnection section.

As shown in FIG. 5, the heat receiving portion 28 of the first heat sink26 includes a first connector 36. The first connector 36 has a pluralityof connection terminals 37 including power supply terminals, groundterminals, signal terminals for fan control, and signal terminals forrecognizing the coupling of the cooling apparatus 2. These connectionterminals 37 are arranged and aligned in a row at a position adjacent tothe heat connection surface 34. The first connector 36 is electricallyconnected to the circuit board 16 through a cable 38 (shown in FIG. 12),and the power supply and various signals are supplied from this circuitboard 16.

As shown in FIG. 8, the heat exchanging portion 29 is integrated withthe heat receiving portion 28 and thermally connected to the heatreceiving portion 28. The heat exchanging portion 29 has a cooling airpassage 40. The cooling air passage 40 communicates with a cooling airexit 41 opening on the left side wall 7 d of the housing 7.

As obvious from FIG. 3, the aforementioned electric fan 27 is positionedin front of the first heat sink 26. The electric fan 27 includes a fancasing 45 and a centrifuge impeller 46. The fan casing 45 is integratedwith the first heat sink 26 and has a first suction port 47, a secondsuction port 48, and a discharge port 49. The first suction port 47 isopposed to a plurality of first air intake ports 51 opening at thebottom wall 7 a of the housing 7. The second suction port 48 ispartially opposed to a plurality of second air intake ports 52 openingon the palm rest 8. The discharge port 49 is opened toward the firstheat sink 26 and the semiconductor package 23, and a part thereof isopposed to the upstream end of the cooling air passage 40.

The impeller 46 is supported on the fan casing 45 through a flat motor53 and positioned between the aforementioned first suction port 47 andsecond suction port 48. The flat motor 53 is rotated based on a signalsupplied from the circuit board 16 when the temperature of thesemiconductor package 23 reaches a predetermined value.

When the impeller 46 is rotated by driving through the flat motor 53,air is pulled from the first and second suction ports 47, 48 toward theimpeller 46. This air is discharged from the outer periphery of theimpeller 46 and delivered to the cooling air passage 40 and thesemiconductor package 23 through the discharge port 49.

As obvious from FIG. 3 to FIG. 5, the bottom wall 7 a of the housing 7has an opening 55. The opening 55 is positioned in the latter halfsection of the bottom wall 7 a so as to correspond to the heatconnection surface 34 of the first heat sink 26. The opening 55 has anopening shape larger than the heat connection surface 34. This opening55 is covered with a cover 56. The cover 56 has a flat plate shape tofit correctly into the opening 55, and is fixed to the bottom wall 7 athrough a screw 57.

The cover 56 has a plurality of through holes 58 and a connector deliverport 59. The through holes 58 are arranged in a matrix, and the heatconductive sheet 35 is exposed outside the housing 7 through thesethrough holes 58. The connector delivery port 59 is opposed to the firstconnector 36, and the connection terminals 37 of the first connector 36is exposed outside the housing 7 through this connector delivery port59.

As shown in FIG. 2, FIG. 3 and FIG. 6, the cooling apparatus 2 forcooling the portable computer 1 includes a flat box-shape apparatus mainbody 61. The apparatus main body 61 has a bottom wall 61 a, a top wall61 b, a front wall 61 c, right and left side walls 61 d and a back wall61 e and is defined to a size corresponding to the latter half sectionof the aforementioned housing 7. Therefore, the apparatus main body 61is set to a size approximately half of the housing 7. The shape of itstop wall 61 b has a rectangular shape extending in the width directionof the housing 7.

The apparatus main body 61 has a flat rest section 62. The rest section62 is the one where the latter half section of the housing 7 restsdetachably, and is constituted by the top wall 61 b of the apparatusmain body 61. The rest section 62 is inclined downward gradually fromthe rear end to the front end thereof, when the apparatus main body 61is put on a horizontal installation surface 63 such as desk top, forexample. As a result, when the housing 7 of the portable computer 1 isput on the rest section 62, as shown in FIG. 7, the portable computer 1is inclined to a posture where the side of the palm rest 8 and thekeyboard 11 becomes low, thereby improving the manipulability during theinput operation.

A pair of fixing hooks 64 a, 64 b are arranged at the rear end of therest section 62. The fixing hooks 64 a, 64 b are separated from eachother in the width direction of the rest section 62, and the rear endsection of the bottom wall 7 a of the housing 7 is detachably hooked tothese fixing hooks 64 a, 64 b.

A pair of movable hooks 65 a, 65 b are arranged at the front end of therest section 62. The movable hooks 65 a, 65 b are arranged separatelyfrom each other in the width direction of the rest section 62. Thesemovable hooks 65 a, 65 b are supported slidably forward and backwardfrom a lock position to be hooked respectively to the bottom wall 7 a ofthe housing 7, and an unlock position disengaging from the bottom wall 7a.

A cooperation hook 66 is arranged in a middle section along the widthdirection of the rest section 62. The cooperation hook 66 has an armsection 67 (shown in FIG. 10 or FIG. 11) along the bottom wall 61 a ofthe apparatus main body 61. The arm section 67 is supported rotatably bythe bottom wall 61 a of the apparatus main body 61 at the end sectionopposite to the cooperation hook 66. Therefore, the cooperation hook 66is rotatable forward and backward from a lock position (shown in FIG.11) to be hooked to the bottom wall 7 a of the housing 7, and an unlockposition (shown in FIG. 10) disengaging from this bottom wall 7 a.

As shown in FIG. 3, FIG. 8 and FIG. 9, the apparatus main body 61 has abuilt-in first cooling module 70. The first cooling module 70 isconfigured to cool the semiconductor package 23 in cooperation with thecooling unit 25 of the portable computer 1. The first cooling module 70includes a second heat sink 71 and an electric fan 72 as a coolingdevice to be driven electrically.

The second heat sink 71 is constituted by a metal material excellent inheat conductivity, such as aluminum alloy, for example. This second heatsink 71 has a flat plate shape having a heat receiving portion 73 and aheat exchanging portion 74. The second heat sink 71 is arranged inparallel to the rest section 62 of the apparatus main body 61 at aposition shifted to the left from the middle section along the widthdirection of the apparatus main body 61.

The heat receiving portion 73 and the heat exchanging portion 74 arearranged in the longitudinal direction of the apparatus main body 61,and positioned on the same plane to each other. The heat receivingportion 73 faces a square opening 75 opened in the top wall 61 b of theapparatus main body 61. As a result, the heat receiving portion 73 ispositioned under the heat connection surface 34 of the aforementionedfirst heat sink 26, when the housing 7 is put on the rest section 62.

A plurality of heat receiving convex sections 77 are formed integrallyon the top face of the heat receiving portion 73. The heat receivingconvex section 77 has a prism shape that may be inserted into thethrough hole 58 of the cover 56 respectively. These heat receivingconvex sections 77 are ejected vertically from the top face of the heatreceiving portion 73 and arranged in a matrix. The tip of the heatreceiving convex section 77 includes a flat contact surface 77 a. Theseflat contact surfaces 77 a are positioned on the same plane.

The heat exchanging portion 74 is positioned behind the heat receivingportion 73. A cooling air passage 78 is formed at the rear end sectionof the heat exchanging portion 74. The cooling air passage 78 extends inthe width direction of the apparatus main body 61, and has a cooling airintake port 79 and a cooling air discharge port 80, as shown in FIG. 8.The cooling air intake port 79 is opened inside the apparatus main body61. The cooling air discharge port 80 is positioned at the side oppositeto the cooling air intake port 79, and faces a cooling air outlet 81opened on the left side wall 61 of the apparatus main body 61.

As shown in FIG. 3 and FIG. 9, the heat receiving portion 73 of thesecond heat sink 71 is provided with a second connector 83. The secondconnector 83 has a plurality of pin shaped connection terminals 84including power supply terminals, ground terminals, signal terminals forfan control, and signal terminals for recognizing the coupling of thecooling apparatus 2. These connection terminals 84 are arranged andaligned in a row at the front end section of the heat receiving portion73. These connection terminals 84 are constituted so as to face theconnection terminals 37 of the first connector 36, when the housing 7 isput on the aforementioned rest section 62.

As shown in FIG. 10, a cable 85 connected to the second connector 83 iselectrically connected to a relay substrate 86. The relay substrate 86is fixed is to the right end section of the bottom wall 61 a of theapparatus main body 61.

As obvious from FIG. 8 to FIG. 10, the aforementioned electric fan 72 isindependent from the second heat sink 71, and is positioned at themiddle section along the width direction of the apparatus main body 61.The electric fan 72 includes a fan casing 88 and a centrifuge typeimpeller 89 housed in this fan casing 88.

The fan casing 88 is fixed to the bottom wall 61 a of the apparatus mainbody 61, at the right of the second heat sink 71. This fan casing 88 hasa first suction port 90, a second suction port 91, and a discharge port92.

The first suction port 90 faces a first draft hole 93 opened on thebottom wall 61 a of the apparatus main body 61. The first draft hole 93has an opening shape larger than the fan casing 88 and is covered with anet shaped fan cover 94. The second suction port 91 faces a plurality ofsecond draft holes 95 opened on the rest section 62. The second draftholes 95 are configured to face the bottom wall 7 a of the housing 7,when the housing 7 of the portable computer 1 rests on the rest section62. The discharge port 92 is opened toward the cooling air intake port79 of the cooling air passage 78.

The impeller 89 is supported on the fan casing 88 through a flat motor96 and positioned between the first and second intake ports 90, 91. Theflat motor 96 has a cable 97 (shown in FIG. 10 and FIG. 11) pulledoutward the fan casing 88. This cable 97 is connected to the relaysubstrate 86.

A switch 100 is mounted on the relay substrate 86. The switch 100 has anoperation lever 101 for opening/closing a circuit for electricallyconnecting the cables 85, 97. When the circuit on the relay substrate 86is closed through this operation lever 101, the second connector 83 andthe flat motor 96 become electrically conductive. Therefore, the flatmotor 96 is supplied with power supply voltage and various signals fromthe second connector 83.

As shown in FIG. 9, the bottom wall 61 a of the apparatus main body 61has four boss sections 103 a to 103 d protruding upward. The bosssections 103 a to 103 d are slidably inserted into four guide holes 104a to 104 d opened in the second heat sink 71. Consequently, the secondheat sink 71 is held vertically movable on the bottom wall 61 a of theapparatus main body 61 taking the boss sections 103 a to 103 d as guide.

A cover plate 106 is affixed at the top end of the boss sections 103 ato 103 d through a plurality of screws 105. The cover plate 106 covers apart of the heat receiving portion 73 and heat exchanging portion 74from the top, and is exposed to the rest section 62 through theaforementioned opening 75. The cover plate 106 has an opening 107avoiding the aforementioned heat receiving convex sections 77 and thesecond connector 83. Consequently, the second heat sink 71 is interposedbetween the bottom wall 61 a of the apparatus main body 61 and the coverplate 106, and pushed up toward the cover plate 106 by compression coilsprings 108.

As shown in FIG. 3, in a state where the second heat sink 71 is pushedup by the compression coil springs 108, the heat receiving convexsections 77 are ejected from the opening 107, and the contact surface 77a of these heat receiving convex sections 77 project over the restsection 62. When the heat receiving convex sections 77 are pushed down,the second heat sink 71 goes down in a way to approach the bottom wall61 a, and the compression coil springs 108 are compressed.

Thereby, the second heat sink 71 is vertically movably supported by theapparatus main body 61 from a thermal connection position wherein thecontact surface 77 a of the heat receiving convex sections 77 projectsover the rest section 62 to a housing position where the contact surface77 a of the heat receiving convex sections 77 sinks to a positionapproximately flush with the top face of the rest section 62.

As shown in FIG. 9 to FIG. 11, the apparatus main body 61 has a built-inoperation mechanism 110 for moving vertically the second heat sink 71 tothe thermal connection position or housing position. The operationmechanism 110 has first to third cogs 111 a to 111 c and a slider 112for rotating these first to third cogs 111 a to 111 c.

The first to third cogs 111 a to 111 c are supported rotatably in theaxial direction on three boss sections 113 protruding from the bottomwall 61 a. The first cog 111 a is positioned at the heat exchangeportion 74 of the second heat sink 71. The second cog 111 b and thethird cog 111 c are positioned at the heat receiving portion 73 of thesecond heat sink 71. These cog 111 b and 111 c are separated in thewidth direction of the apparatus main body 61 across the heat receivingconvex sections 77 therebetween. Moreover, the first to third cogs 111 ato 111 c have a flange section 114 at their top end respectively. An endcam 115 is formed at the bottom face of the flange section 114.

The second heat sink 71 has three circular insertion holes 117 atpositions corresponding to the first to third cogs 111 a to 111 c. Theinsertion hole 117 has a diameter larger than the flange section 114 ofthe first to third cogs 111 a to 111 c. A cam receiving section 118projecting radially inside is formed on the inner circumferentialsurface of the respective insertion holes 117. The cam receiving section118 is slidably in contact with the end cam 115 of the flange section114.

As shown in FIG. 10 and FIG. 11, the aforementioned slider 112 issupported by the bottom wall 61 a slidably in the width direction of theapparatus main body 61. The slider 112 has a strip shape extending inthe width direction of the apparatus main body 61 and a finger hooksection 119 exposed to the bottom wall 61 a of the apparatus main body61 at the right end section thereof.

The slider 112 has a rack section 121 as shown in FIG. 9 at the left endsection thereof. The rack section 121 penetrates under the second heatsink 71, and is introduced between the first to third cogs 111 a to 111c. The rack section 121 has first to third rack teeth 122 a to 122 c.The first to third rack teeth 122 a to 122 c mesh with the first tothird cogs 111 a to 111 c respectively. Consequently, when the slider112 slides, the linear movement of this slider 112 is converted intorotation movement and conducted to the first to third cogs 111 a to 111c, and these first to third cogs 111 a to 111 c are configured tocooperate and rotate around the axis over a predetermined angular range.

When the first to third cogs 111 a to 111 c rotate, the relativepositional relation between the end cam 115 and the cam receivingsection 118 of the second heat sink 71 varies. To be more specific, theend cam 115 is continuously inclined so as to project under the flange114. Therefore, when the cam receiving section 118 comes into contactwith the portion of minimum downward projection of the end cam 115, thesecond heat sink 71 is pushed up to the heat connection position underthe energizing force of the compression coil springs 108. On thecontrary, when the cam receiving section 118 comes into contact with theportion of maximum downward projection of the end cam 115, the secondheat sink 71 receives a force for pressing toward the bottom wall 61 aagainst the energizing force of the compression coil springs 108.Thereby, the second heat sink 71 goes down to the housing position.

Given this, the slider 112 is supported by the apparatus main body 61linearly slidably from a first position for pushing up the second sink71 to the heat connection position (shown in FIG. 11) and a secondposition for submerging the second heat sink 71 to the housing position(shown in FIG. 10).

The slider 112 traverses over the arm section 67 of the cooperation hook66, and the slider 112 has a slit shape cam hole 123 at a positioncorresponding to the arm section 67. The arm section 67 has a pin shapeguide projection 124 protruding upward. The guide projection 124 isslidably inserted into the cam hole 123. Therefore, the arm section 67of the cooperation hook 66 is constituted so as to rotate forcibly basedon the shape of the cam hole 123 when the slider 112 is slid. Thereby,the cooperation hook 66 moves to the lock position shown by FIG. 11 whenthe slider 112 is slid to the first position, and moves to the unlockposition shown by FIG. 10 when this slider 112 is slid to the secondposition.

The right end section of the slider 112 is positioned just before theaforementioned relay substrate 86. A pressure section 126 is formedintegrally with the right end section of this slider 112. The pressuresection 126 presses the operation lever 101 of the aforementioned switch100, when the slider 112 is slid to the first position shown in FIG. 11.This pressure closes the switch 100 and connects electrically theelectric fan 72 and the second connector 83.

The pressure section 126 is disengaged from the operation lever 101 ofthe switch 100 when the slider 112 is slid to the second position shownin FIG. 10. Thereby, the operation lever 101 returns to the homeposition to open the switch 100, and interrupts the electricalconnection between the electric fan 72 and the second connector 83.

The aforementioned expansion apparatus 3 for expanding the function ofthe portable computer 1 is detachably coupled with the portable computer1 in exchange to the aforementioned cooling apparatus 2. This expansionapparatus 3 is provided with a flat box-shape base 150 as shown in FIG.13 and FIG. 14. The base 150 has a bottom wall 150 a, a top wall 150 b,a front wall 150 c, right and left side walls 150 d, and a back wall 150e, and is defined to a size corresponding to the housing 7 of theportable computer 1.

The base 150 is provided with a rest section 151 where the housing 7 isput detachably. The rest section 151 is constituted by the upper wall150 b of the base 150, and has a size approximately equal to the bottomwall 7 a of the housing 7.

The base 150 has a DVD drive unit 152 and a circuit board 153 (shown inFIG. 18 and FIG. 19) inside. The DVD drive unit 152 is an element forexpanding the function of the portable computer 1 and electricallyconnected to the circuit board 153. The circuit board 153 is arranged inparallel to the bottom wall 150 a at the rear section of the base 150,and a second expansion connector 155 is mounted on the top face of thecircuit board 150. The second expansion connector 155 projects on therest section 151.

Therefore, if the housing 7 of the portable computer 1 is put on therest section 151, as shown schematically in FIG. 19, the first expansionconnector 17 and the second expansion connector 155 engage with eachother. Thereby, the portable computer 1 and the expansion apparatus 3are electrically connected through the first and second expansionconnectors 17, 155, and the signal path of various control signals, suchas logic address, or data bus of them both becomes electricallyconductive.

Further, a power supply connector (not shown) is mounted on the rear endsection of the circuit board 153. The power supply connector isconfigured to connect a power supply cord and is exposed on the rearwall 150 e of the base 150. The power supply connector is electricallyconnected to the power supply circuit on the circuit substrate 153.

As shown in FIG. 14, a pair of guide protrusions 156 a, 156 b to beengaged detachably with the front wall 7 c of the housing 7 are arrangedat the front end of the rest section 151. Further, a pair of lock levers157 a, 157 b are arranged at the rear end of the rest section 151. Thelock levers 157 a, 157 b are constituted so as to lock the portablecomputer 1 on the rest section 151. The lock levers 157 a, 157 b aresupported on the base 150 movably between a lock position to engage withthe bottom wall 7 a of the housing 7 of the portable computer 1, and anunlock position to separate from the bottom wall 7 a.

As shown in FIG. 15 to FIG. 17, the base 150 has a built-in secondcooling module 161. The second cooling module 161 is constituted so asto support the cooling of the portable computer 1 and includes a thirdheat sink 162 and an electric fan 163.

The third heat sink 162 is constituted by a metal material excellent inheat conductivity, such as aluminum alloy, for example, and has a flatplate shape. The third heat sink 162 is arranged in parallel to thebottom wall 150 a of the base 150, and a pedestal section 164 projectingupward is formed integrally with the top face thereof. The pedestalsection 164 is exposed on the rest section 151 through an opening 165opened at the top wall 150 b. Consequently, the pedestal section 164 ispositioned under the heat connection surface 34 of the aforementionedfirst heat sink 26, when the housing 7 of the portable computer 1 is puton the rest section 151.

The pedestal section 164 has integrally a plurality of heat receivingconvex sections 166. The heat receiving convex sections 166 formrespectively a prism that may be inserted into the through hole 58 ofthe aforementioned cover 56. The heat receiving convex sections 166 arearranged in a matrix, and project vertically from the top face of thepedestal 164. The tip of each heat receiving convex section 166 includesa flat contact surface 166 a. These contact surfaces 166 a arepositioned on a same plane.

As shown in FIG. 15 and FIG. 16, the third heat sink 162 has a coolingair passage 167. The cooling air passage 167 is positioned under theheat receiving convex sections 166. The cooling air passage 167 has acooling air outlet 168 opened toward the left side wall 150 d of thebase 150. The cooling air outlet 168 communicates with an exhaust port169 opened on the side wall 150 d.

A plurality of slide guides 171 are supported vertically slidable by thethird heat sink 162. The slide guides 171 are positioned around theaforementioned pedestal 164. These slide guides 171 are fixed to aplurality of boss sections 172 projecting upward from the bottom wall150 a through screws 173. A plurality of compression coil springs 174are interposed between the lower end of the slide guides 171 and thebottom face of the third heat sink 162. The compression coil springs 174push up the third heat sink 162 towards the rest section 151.

Consequently, when the third heat sink 162 is pressed downward, thecompression coil springs 174 are compressed, and the third heat sink 162goes down in a way to approach the bottom wall 150 a of the base 150along the slide guides 171. Thereby, the third heat sink 162 isvertically movable from a thermal connection position wherein the heatreceiving convex sections 166 projects over the rest section 151 to ahousing position where the pedestal section 164 goes down inside thebase 150, and is always held at the thermal connection position.

As shown in FIG. 16, the aforementioned electric fan 163 is positionedat the side opposed to the aforementioned cooling air outlet 168 acrossthe cooling air passage 167. The electric fan 163 includes a fan casing176 and a centrifuge-type impeller 177. The fan casing 176 is integratedwith the third heat sink 162. The fan casing 176 has a first suctionport 178, a second suction port 179, and a discharge port 180. The firstsuction port 178 faces a plurality of first air inlet ports 181 openedat the bottom wall 150 a. The second suction port 179 faces a pluralityof second air inlet ports 182 opened on the top wall 150 b. Thedischarge port 180 communicates with the upstream end of the cooling airpassage 167.

The impeller 177 is supported on the fan casing 176 through a flat motor183. The flat motor 183 has a cable 185 (shown in FIG. 18 and FIG. 19)pulled outside the fan casing 176. The cable 185 includes a signal linefor supplying power supply voltage, and a signal line for carrying asignal for controlling the rotation of the impeller 177. The cable 185is electrically connected to the aforementioned circuit board 153.

The flat motor 183 is rotated when the temperature of the semiconductorpackage 23 reaches a predetermined value. When the impeller 177 isrotated by driving the flat motor 183, air is pulled from the first andsecond suction inlets 178, 179 toward the impeller 177. The air isdischarged from the outer circumferential section of the impeller 177,and delivered to the cooling air passage 167 through the discharge port180.

Now, the procedures to use by coupling the portable computer 1 with thecooling apparatus 2 will be explained.

First, the slider 112 (see FIG. 10 and FIG. 11) of the cooling apparatus2 is slid to the second position. So long as this slider 112 is in thesecond position, the second heat sink 71 goes down to the housingposition and the cooperation hook 66 is held in the unlock position.

In this state, the fixing hooks 64 a, 64 b positioned at the rear end ofthe rest section 62 are engaged with the bottom wall 7 a of the housing7, and the cooling apparatus 2 and the housing 7 are rotated in adirection for approaching each other taking the engagement section ofthis fixing hook 64 a, 64 b and the bottom wall 7 a as fulcrum. Thisrotation engages movable hooks 65 a, 65 b with the bottom wall 7 a, andthe housing 7 of the portable computer 1 is coupled with the restsection 62 of the cooling apparatus 2.

Next, the slider 112 is slid form the second position to the firstposition. There, the cooperation hook 66 rotates from the unlockposition to the lock position, and engages with the bottom wall 7 a ofthe housing 7. Thereby, the housing 7 is locked undetectably on the restsection 62.

At the same time, the first to third cogs 111 a to 111 c meshing withthe first to third rack teeth 122 a to 122 c rotate, and the second heatsink 71 is pushed up from the housing position to the thermal connectionposition according to the shape of its end cam 115. Thereby, the contactsurface 77 a of the heat receiving convex sections 77 passes through thethrough holes 58 and comes into contact with the heat conductive sheet35. The heat conductive sheet 35 follows the shape of the heatconnection surface 34 and the contact surface 77 a and comes into aclose contact with both of them, and connects thermally the first heatsink 26 with the second heat sink 71.

When the second heat sink 71 is pushed up to the thermal connectionposition, as shown in FIG. 7, the connection terminals 84 of the secondconnector 83 come into contact with the connection terminals 37 of thefirst connector 36 through the connector delivery port 59. At the sametime, the operation lever 101 of the switch 100 is pressed by thepressure section 126 of the slider 112, to close the switch 100.

Thereby, as shown schematically in FIG. 12, the circuit board 16 of theportable computer 1 and the electric fan 72 of the cooling module 70 areelectrically connected. As a result, the power supply, the ground, therotation control signal for keeping the rotation of the impeller 89 to afixed value, and the recognition signal for determining the couplingstate of the cooling apparatus 2 are transmitted/received between theelectric fan 72 and the circuit board 16. The recognition signal is asignal for recognizing that the portable computer 1 is correctly coupledwith the rest section 62 of the cooling apparatus 2. When the portablecomputer 1 recognizes the completion of coupling with the coolingapparatus 2 by transmission/reception of the recognition signal, theflat motor 96 is supplied with power supply voltage, and the electricfan 72 shifts to a standby state.

When the portable computer 1 is coupled with the cooling apparatus 2, ifthe IC chip 24 of the semiconductor package 23 generates heat, heat fromthis IC chip 24 is conducted to the heat receiving portion 28 of thefirst heat sink 26 through the heat dissipation plate 31 and the grease32. Further, the heat is conducted to the second heat sink 71 of thecooling apparatus 2 from the heat receiving portion 28 through the heatconductive sheet 35, and released therefrom.

When the temperature of the semiconductor package 23 reaches apredetermined value, the electric fan 27 of the cooling unit 25 and theelectric fan 72 of the cooling apparatus 2 start to drive according tothe signal from the circuit board 16. The electric fan 27 built in thehousing 7 delivers air pulled from the first and second suction ports47, 48 as cooling air to the cooling air passage 40 of the first heatsink 26 and the semiconductor package 23 through the discharge port 49.The cooling air cools down the semiconductor package 23, and cools downthe heat exchanging portion 29 of the first heat sink 26 in the courseof flowing through the cooling air passage 40. Much of this cooling airis discharged outside the housing 7 from the cooling air outlet 41.

The electric fan 72 built in the cooling apparatus 2 delivers air pulledfrom the first and second suction ports 90, 91 as cooling air to thecooling air passage 78 of the second heat sink 71. The cooling air coolsdown the heat exchanging portion 74 in the course of flowing through thecooling air passage 78. This cooling air is discharged outside theapparatus main body 61 from the cooling air discharge port 80 throughthe cooling air outlet 81.

Therefore, heat from the semiconductor package 23 conducted to thesecond heat sink 71 is released outside the cooling apparatus 2 borne bythe flow of the cooling air. Moreover, as the first heat sink 26 isinterposed between the semiconductor package 23 and the second heat sink71, the heat capacity of the heat radiation path from the semiconductorpackage 23 to the second heat sink 71 is increased. Therefore, thesemiconductor package 23 may be cooled down effectively.

As mentioned above, in a mode of utilization by coupling the portablecomputer 1 with the cooling apparatus 2, the cooling of thesemiconductor package 23 may be maintained by using the first coolingmodule 70 built in the cooling apparatus 2. As a result, the operationenvironment temperature of the semiconductor package 23 may bemaintained appropriately, by enhancing the cooling performance thereof,and the reliability of the portable computer 1 when operated at fullpower may be improved.

Next, the procedures for expanding the function of the portable computer1 using the expansion apparatus 3 shall be described.

When the cooling apparatus 2 is coupled with the portable computer 1,first, the slider 112 (see FIG. 10 and FIG. 11) is slid from the firstposition to the second position. This sliding rotates the cooperationhook 66 from the lock position to the unlock position, and disengagesthe same from the bottom wall 7 a of the housing 7. Thereby, the secondheat sink 71 goes down to the housing position, the thermal connectionwith the first heat sink 26 is released, and the connection terminals 84of the second connector 83 disengages from the connection terminals 37of the first connector 36.

Therefore, the cooling apparatus 2 may be removed from the portablecomputer 1 by moving the movable hooks 65 a, 65 b from the lock positionto the unlock position.

When the removal of the cooling apparatus 2 is completed, the housing 7of the portable computer 1 is directed to the rest section 151 of thebase 150, and the front wall 7 c of the housing 7 is hooked to the guideprojections 156 a, 156 b at the front end of the rest section 151. Inthis state, the housing 7 is rotated downward taking the engagementsection of the front wall 7 c and the guide projections 156 a, 156 b asa fulcrum, and the housing 7 is overlapped on the rest section 151.Thereby, the lock levers 157 a, 157 b are hooked on the bottom wall 7 aof the housing 7, and the portable computer 1 is locked on the restsection 151. At the same time, the shutter 19 opens to expose the firstexpansion connector 17, and this first expansion connector 17 and thesecond expansion connector 155 engage with each other.

The engagement of these expansion connectors 17, 155 electricallyconnect the portable computer 1 and the expansion apparatus 3, as shownschematically in FIG. 19. Therefore, the exchange of control signalsbetween both of them is made possible, and expansion elements of theportable computer 1, such as a DVD drive unit 152, may be supported.

Further, the second expansion connector 155 is electrically connected tothe electric fan 163 through the circuit board 153 and the cable 185.The cable 185 has a signal line for rotation control to maintain therotation of the impeller 177 at a fixed value. The power supply, theground, and the rotation control signal are transmitted/received betweenthe circuit board 16 of the portable computer 1 and the electric fan163, and the electric fan 163 shifts to a standby state.

When the housing 7 of the portable computer 1 is locked on the restsection 151, the heat receiving convex sections 166 of the third heatsink 162 comes into contact with the heat conductive sheet 35 throughthe through holes 58 of the cover 56. The heat receiving convex sections166 are pressed downward by the contact with the heat conductive sheet35, and by this pressure, the second cooling module 161 goes downagainst the energizing force of the compression coil springs 174.Consequently, the heat receiving convex sections 166 are elasticallyapplied to the heat conductive sheet 35 by the compression coil springs174.

As the result, the heat conductive sheet 35 follows the shape of theheat connection surface 34 or the contact surface 166 a and comes into aclose contact with both of them, and thermally connects the first heatsink 26 and the third heat sink 162.

When the portable computer 1 is used by coupling with the expansionapparatus 3, if the IC chip 24 of the semiconductor package 23 generatesheat, heat from the IC chip 24 is conducted to the heat receivingportion 28 of the first heat sink 26 through the heat dissipation plate31 and the grease 32. Further, the heat is conducted to the third heatsink 162 of the expansion apparatus 3 from the heat receiving portion 28through the heat conductive sheet 35, and released therefrom.

When the temperature of the semiconductor package 23 reaches apredetermined value, the electric fan 27 of the cooling unit 25 and theelectric fan 163 of the expansion apparatus 3 start to driverespectively according to the signal from the circuit board 16. Theelectric fan 27 delivers cooling air to the cooling air passage 40 ofthe first heat sink 26 and the semiconductor package 23, and cools downforcibly both of them. The electric fan 163 of the expansion apparatus 3delivers air pulled from the first and second suction ports 178, 179 ascooling air to the cooling air passage 167 of the third heat sink 162.The cooling air cools down the third heat sink 162 in the course offlowing through the cooling air passage 167, and is discharged outsidethe base 150 from the cooling air outlet 168 through the exhaust port169.

Therefore, heat from the semiconductor package 23 conducted to the thirdheat sink 162 is released outside the expansion apparatus 3 borne by theflow of the cooling air. Moreover, as the first heat sink 26 isinterposed between the semiconductor package 23 and the third heat sink162, the heat capacity of the heat radiation path from the semiconductorpackage 23 to the third heat sink 162 is increased. Therefore, thesemiconductor package 23 may be cooled down more effectively.

As mentioned above, in a mode of utilization by coupling the portablecomputer 1 with the expansion apparatus 3, the cooling of thesemiconductor package 23 may be supported by using the second coolingmodule 161 built in the expansion apparatus 3. As a result, theoperational environment temperature of the semiconductor package 23 maybe maintained appropriately by enhancing the cooling performancethereof, and the reliability of the portable computer 1 when operated atfull power may be improved.

By the way, according to the electronic system of the aforementionedembodiment, in a state where the portable computer 1 is coupled to acooling apparatus 2 or an expansion apparatus 3, the powering of thecooling module 70 of the cooling apparatus 2, the DVD drive unit 152 ofthe expansion apparatus 3, or the second cooling module 161 may becontrolled by the portable computer 1. Therefore, a single portablecomputer 1 may support both the cooling apparatus 2 and the expansionapparatus 3, and the cooling apparatus 2 and the expansion apparatus 3may be used freely depending on the mode of use of the portable computer1.

In addition, as the electric fan 72 built in the cooling apparatus 2receives power supply voltage or various control signals from theportable computer 1, the electric fan 72 may be controlled and poweredby the portable computer 1. Therefore, it is unnecessary to arrangepower supply for powering, or to have circuit components for control ofthe electric fan 72 in the apparatus main body 61 of the coolingapparatus 2, and this apparatus main body 61 may be formed lighter andsmaller than the housing 7 of the portable computer 1.

Therefore, in a case of adhering to the importance particularly to theportability of the portable computer 1, it is possible to carry theportable computer 1 easily, while still maintain a cooling performancesufficient for utilizing the full capacity of the semiconductor package23 by using the cooling apparatus 2 at the same time.

Further, since both of the electric fan 72 of the cooling apparatus 2and the electric fan 163 of the expansion apparatus 3 receive a rotationcontrol signal from the portable computer 1, excess revolutions of theelectric fans 72, 163 may be controlled. In short, the electric fans 72,163 tend to increase the revolutions of the impeller 89, 177 even whenthe driving voltage is kept constant, because, in general, the greaseadapts itself to the rotating portions thereof to be lubricated as theoperation time elapses. Consequently, if the revolutions of theimpellers 89, 177 happen to exceed an appropriate value, it may causenoise.

However, according to the aforementioned embodiment, the revolutions ofthe impeller 89, 177 may be controlled at an appropriate value, and theoperation noise of the electric fans 72, 163 may be reduced.

It should be appreciated that the present invention is not limited tothe aforementioned embodiment, but it may be modified without departingfrom the scope of the subject matter of the present invention.

For instance, though in the aforementioned embodiment, the first andsecond connectors are built integrally with the first and second heatsinks respectively, these first and second connectors may also bemounted on the bottom wall of the housing and the apparatus main bodyrespectively.

Besides, the second and third heat sinks are not necessarily movable upand down, but they may also be affixed rigidly to the rest section ofthe cooling apparatus and the expansion apparatus respectively.

Moreover, the electrically driven cooling device is not limited to theelectric fan, but it may also be an electric coolant circulation modulefor circulating, for example, a liquid coolant.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details and representative embodiments shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An expansion apparatus detachably capable ofbeing connected to a portable electronic apparatus having a built-inheat generating component and a first expansion connector for functionexpansion, said expansion apparatus comprising: a base having an exhaustport and a rest section on which the portable electronic apparatus isplaced; a least one functional component housed in the base to expandfunction of the portable electronic apparatus; a cooling module housedin the base, including a heat sink having a cooling air passage and aheat receiving section exposed to the rest section, and an electric fanto supply cooling air to the cooling air passage, the heat receivingsection of the heat sink being thermally connected to the heatgenerating component when the portable electronic apparatus is placed onthe rest section; and a second expansion connector placed in the restsection of the base, the second expansion connector being electricallyconnected to the functional component and the electric fan, and thesecond expansion connector being connected to the first expansionconnector when the portable electronic apparatus is placed in the restsection, whereby the second expansion connector receives power from thefirst expansion connector to supply the power to the electric fan. 2.The expansion apparatus according to claim 1, wherein when the secondexpansion connector is connected to the first expansion connector, theelectric fan receives a signal from the portable electronic apparatusfor controlling the number of rotations.
 3. The expansion apparatusaccording to claim 1, wherein the heat sink is movable between a firstposition where the heat receiving portion is projected over the restsection and a second position below the first position where the heatreceiving portion rests toward the rest section.
 4. The expansionapparatus according to claim 3, wherein the heat sink is elasticallyurged toward the first position via springs.